A bicycle is the most energy efficient vehicle devised to date, perhaps ever. According to Eric Sorenson & the Sightline Institute in Seven Wonders for a Cool Planet, "A human on a bicycle is more efficient (in calories expended, per pound, per mile) than a train, truck, airplane, boat, automobile, motorcycle, skateboard, canoe or jet. Cycling is more efficient than walking which takes three times as many calories per mile. Pound for pound a person riding a bike can go further on a calorie of food than a gazelle can running, a salmon swimming, or an eagle flying."

When Pennsylvania couldn’t afford a long-planned, $465 million freeway north of Philadelphia, Biehler brainstormed with communities along the 8.4-mile route and found a cheaper alternative: a parkway bordered with trees and bike trails. Work on the $200 million project began in November.